It has long been suspected that infections acquired during a hospital stay are a major health care issue. Until recently hard data has not been available to demonstrate just how serious this problem has become. Pennsylvania was the first state to collect data tracking numbers and the results of hospital-acquired infections. The results are staggering.
For instance, applicants understand that this collected data shows that in 2004, at least 12,000 patients in Pennsylvania developed infections while in a hospital. Fifteen hundred, or about 12.5%, of those patients died. Two billion dollars in extra medical care was required to treat these patients. If these numbers are extrapolated to the rest of the U.S., nearly 100 patients are dying per day and an extra 50 billion dollars are being spent per year to fight hospital-acquired infections. The Center for Disease Control and Prevention estimates as many as two million infections are acquired in U.S. hospitals each year, resulting in approximately 90,000 deaths.
It is generally recognized that hypothermic patients are more susceptible to infection. Nonetheless, keeping the core body temperature properly regulated has grown to be the standard of care in almost every hospital and surgery center. An added benefit to keeping a patient properly regulated is the time required in Post Anesthesia Care Unit (“PACU”) areas. When a patient moves from surgery through the PACU faster, more surgeries can be performed in the same amount of time. This makes each surgery more cost-effective.
One historical difficulty with medical patient temperature therapy is contamination. This issue exists for water systems as well as convective air systems, i.e. systems with closed loop fluid flow. For example, water based hypo-hyperthermia systems can be a perfect breeding ground for bacteria. Bacteria can also collect in convective warming devices. Almost all the air drawn into current version blowers gets filtered through HEPA level filtration. This is a great initial step for cleaning up the air that is provided to the patient. Nonetheless, poor maintenance practices can negate the overall effectiveness of these filters. Contaminates can enter the unit during maintenance or manufacturing, while the filter is removed. Contaminates can also enter the hose between uses. And once these contaminates have found their way into these types of devices, the warmed atmosphere may actually assist in their further growth. Applicant is aware of information that seems to indicate that a convective system may be to blame for elevated infection rates at a hospital in Denver.
Water based systems also have comparable challenges for staying safely clean. When a water based device is cleaned, it is not practical to expect that every part of the surface area that can harbor algae or bacteria will be properly exposed to disinfectants to sanitize the system. This is especially true when fundamental mistakes are made during the cleaning process. Often, the connecting water hoses are not cleaned. If a reusable water blanket is used, the internal surface of the blankets are often not cleaned sufficiently. So if these components are not clean to begin with, the circulating water will certainly not stay clean. Moreover, there are also known instances where the distilled water used in such devices arrived at the hospital in a contaminated condition. This contaminated water was then used in a clean device only to immediately inoculate the system with contaminates. In those situations, the components started out clean, but became contaminated by the water. So although patient temperature therapy is important for patient care, and also helps hospitals reduce overall surgery costs, there is an ongoing and important need to combat hospital infection. There is also an important need to come up with innovative ways to do that, because statistics show that existing procedures are not effective, for a variety of reasons.
Clearly, attempting to keep a warming system clean is a good practice. However, the only way to confidently supply germ-free and alga-free fluid to a patient receiving temperature therapy is to completely clean the fluid just before it comes in close proximity to the patient.
Unfortunately, due to personnel limitations and/or budget restrictions, it is all too common for the fluid circuit of a patient temperature control system to be cleaned either too infrequently or insufficiently. Even with proper cleaning protocols or manufacturer suggestions in place, the cleaning of the circulating fluid of a patient temperature control system will probably not be considered as important as it should be.